|
“Current
Comments On Healthcare IAQ Issuesä”
October 22,
2004
Volume 2 No. 2 |
Entire Hospital Wing or Floor as a Negative Pressure
Environment
This question has arisen more than occasionally recently, “can you make
an entire floor of our hospital into a negative pressure ward?”. The genesis of
this concept was a public address by the Director of the CDC in January, 2003.
Dr. Julie Gerberding suggested the ideal method of containing a large number of
people either infected with a common contagious disease or in the case of a
biochemical attack would be to place them in a common, ward-like, enclosure.
Hospitals today are not built as they were in the early to mid-1900’s with wards
to accommodate tubercular patients. Today there are very few, if any, recently
built hospitals with inclusion of a ward concept of 10 to 50 beds or more.
It is possible to create negative pressure wings or an entire floor (or floors)
of a hospital into a negative pressure environment in relation to the area
immediately outside the isolated section. The hallways would be negative in
relation to the section outside the environment (with multiple 24/7 monitoring
devices), but the rooms in the isolation area would have to be MORE negative
than the hallways and other public parts of the isolated wing/floor.
The general areas could have negative pressure created by a BAS (building
automation system, i.e., Johnson Controls, Siemens, etc.) controlling supply and
returned air or by balancing dampers to create an offset of return air to
supplied air. The room, which must have a more negative environment than the
hallways (and other public areas), would need to be brought up to the new
JCAHO/AIA standards dated 1/1/03 of 12 ACH (air changes per hour) and a negative
0.005” W.C. pressure. These individual rooms would also have to be monitored
24/7 as per JCAHO’S E.C. standard dated 10/1/03.
Most existing hospital AHU’s (air handling units) can be set to give the
negative pressure in the general areas of the wing/floor with few problems, but
most cannot deliver the 12 ACH and/or adequate negative pressure for the
individual rooms. If the hospital was constructed in the last few years, or so,
they may have the capacity to do so, but this is not normally the case for older
facilities.
Modular APS (air purification systems) would generally be the least costly and
most efficient way to handle the individual room ACH and negative pressure
requirements for the rooms involved.
The other challenge would be to totally seal the wing/floor from the area
outside the isolated environment. This takes time and a lot of patience, but it
can be accomplished.
The alternative to isolating a wing or floor of the hospital is to erect a
building outside the facility to house a specific number of patients. This
building would be, in HVAC terms, totally independent of the main air handling
system of the hospital. When not being used for emergency purposes, this area
could be used as an “urgent care center” for non-critical emergency patients or
as an outpatient clinic.
The only source for specifically designed buildings of this type being
commercially sold is Medical Air Solutions of Marietta, GA. They can provide
buildings from 1,000 to 100,000 square feet in size. They are prefabricated and
can be relocated from one area to another. This concept has been designated as
the Emergency Preparedness Isolation Center (E.P.I.C.). Medical Air Solutions,
LLC. can be contacted at 800-645-1059.
For more information, call Medical Air Solutions at 800-645-1059 or
engineering dept. at 770-377-3884.

|